Everyone likes to think their taste in music is unique, but a new study shows that what makes a song stick in your head is often the knowledge that others are humming the same tune.

Sociologists at Columbia University set out to test this theory by dividing 14,000 music-loving teenagers into two groups. They then allowed them to pick out their favorite songs by unknown bands. The experimental setup, carried out over the Internet, offered one group of listeners access to other people’s opinions before they chose their preferred tracks, while other listeners chose their favorites without any outside input.

According to Mathew Salganik, the graduate student who organized the experiment, the group acting under social influence couldn’t get their peer’s favorites out of their heads.

“The more popular songs became more successful, and the less popular songs became even less popular,” said Salganik.

While Salganik could predict which songs would be popular after an initial round of feedback, he said it’s initially difficult to guess which songs will become popular and which will be despised strictly on their own merits. He cites the performance of the song “Lockdown” by 52metro, which ranked right in the middle among the 48 available tracks by listeners who had no social context. However, in two samples subjected to outside influence, it came in first place in one trial and 40th in the other.

The study itself, which appears in the February 10th issue of Science, is unique because Salganik used the Internet to alter experimental conditions, manipulating the information subjects could see.

“It was much more like a lab experiment,” said Duncan Watts, associate professor of sociology at Columbia and a coauthor of the study. “I think that’s pretty new for the Web.”

With the 2006 Grammys already handed out, it makes one wonder, were the awards for “song of the year” (U2’s “Sometimes You Can’t Make It on Your Own”) and “record of the year” (Green Day’s “Boulevard of Broken Dreams”) go to the best songs or the most popular? Can any ol’ song conceivably be nominated and win? Or are the judges only swayed by what’s been at the top of the charts?

Salganik thinks there is a bit of luck involved in any song “making it.”

“This [finding] can be encouraging for aspiring musicians and in some ways disheartening,” he said. “Some things that are very good quality still don’t make it, but if you are in a band and people don’t like you, it doesn’t mean you aren’t very good.”

It isn’t just taste in music that’s influenced by popular opinion. Books, movies and television shows can also become duds or hits based on how we think other people perceive them.

Peter Hedström, a sociologist at Oxford University, said that what becomes a hit is “highly path-dependent, in the sense that early choices or actions often have a disproportionately large impact on the end result.”

So if want to write a hit song, don’t worry about lyrics, chorus or any of that jazz, just make sure to convince the first people to hear it that it’s a chart-topper.